Watching Attorney General Martha Coakley wow a group of health industry types in a Seaport ballroom on Friday, it was easy to see her strengths as a gubernatorial candidate. Which makes her missteps all the more mystifying.

This is the Coakley too few voters saw as she ran and lost a race for the US Senate back in 2010. It’s the Coakley she is determined to show to as many of them as possible now, as she runs for governor. Criticized as aloof and lacking in energy back then, she is now an indefatigable candidate who spent the first three days of her campaign, and plenty of days since, speeding around the state to meet people.

She and her advisers insist that the ghosts of 2010 have been laid to rest. But one of them burst back into view just after Halloween, and it has more potential to spook voters than questions about the candidate’s energy level.

As my colleague Frank Phillips reported, Coakley’s campaign finances from the 2010 race are in some disarray. Among the irregularities: incomes and expenditures are distressingly imbalanced, and $6,000 from her federal campaign fund was used to advance her fortunes as a state candidate, which is a clear campaign finance no-no. Coakley also took the unusual step of hiring her sister to be treasurer of both the federal and state campaigns, though she was paid only from the federal funds. And the campaign did not respond to repeated requests for clarification by the Federal Election Commission.

All innocent errors, her campaign says. They didn’t receive notices because the FEC was using an invalid e-mail address. As soon as they learned about the problems from the Globe, they began correcting them. Coakley’s sister, who worked as a volunteer for the state campaign account, has been replaced.

This is all to the good. But it misses the point. These howlers would be embarrassing for any candidate. For the attorney general of the Commonwealth, they are much worse than that. Enforcing campaign finance laws is her job. An attorney general will always, and rightly, be held to a way higher standard on matters of law. And it should have been obvious to Coakley that it would look bad to put her sister on the campaign payroll, particularly since it’s now clear she was not up to the job.

Coakley, who has spent months — years, actually — beating back claims that she is too distant, hadn’t deigned to publicly address the problems herself, punting the issue to a spokesman until we spoke Friday morning.

“Look,” she said, “there is nothing more important to me . . . as a candidate and as an elected official . . . as making sure we have the appearance of correctness, and that we in fact are correct. So we are going to fix this, and we are going to be transparent about it.”

She hired her sister because she had worked in banking for years, Coakley said: “She is someone I know and trust, and she is qualified,” she said. “This is . . . not something we sat on or ignored; we just found out about it.”

She spoke with admirable directness, which made the delay in taking this on all the more unfathomable.

As the gleeful dispatches from the state Republican Party make clear, the campaign finance mess-ups are a gift for Coakley’s opponents. She has been highly regarded as an attorney general, especially in the last few years, when she threw herself into her job after losing the Senate race. Even her toughest critics have spoken of redemption.

The campaign finance foul-ups go directly to her greatest strength. They dent Coakley’s brand. And it’s going to take more than better accounting to fix that.